In this proposal, specific attention is given to the total synthesis of five uniquely structured terponoid natural products. Two of these, pleuromutilin and ophiobolin F are known to possess very respectable antibiotic and antifungal properties, respectively. Ingenol is a diterpene, several esters of which have been reported to exhibit tumor promotion or anti-leukemic activity depending on their nature. A total synthesis of ingenol, in tandem with the preparation of select esters, could be of substantive value in delineating the structural features which govern this most fascinating split in biological activity. Other synthetic targets include sterpuric acid, a new type of sesquiterpenoid which is responsible for "silver leaf disease" in various fruit and decorative trees, and 3Beta-hydroxy-7Beta-kemp-8(9)-en-6-one, a chemical defense agent of nasute termite soldier ants. The biological activity of the latter two substances has not been explored at all and their novel structural features suggest that broad-screened assays should be carried out. This we hope to achieve with our synthetic material.